Compressed gas cartridge permeation dispenser having a predictable permeation rate

ABSTRACT

A compressed gas cartridge is pierced and dispenses its pressurized gas through a permeation element that serves as a way to regulate the rate of gas dispensed out an outlet in the surrounding housing. It has been found that the use of a permeation element can control the rate of dispensation to an almost constant rate over time, which is valuable in applications such as art preservation for just one example.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Continuation application claiming priority from aU.S. Utility application having Ser. No. 11/213,407 filed Aug. 29, 2005.

FEDERALLY SPONSORED RESEARCH

Not applicable.

REFERENCE TO A MICROFICHE APPENDIX

Not applicable.

FIELD OF INVENTION

The present invention relates to the field of portable compressed gascartridge dispensers comprising the ability to predictably permeate thepressurized gas contained within a compressed gas cartridge.

BACKGROUND OF THE INVENTION

A non all-inclusive variety of applications relevant to the currentpermeation dispenser apply to such applications as maintaining an inertgas environment, plant feeding, aquarium water treatment, constantlubrication delivery, maintaining positive pressures, and many otherapplications as will become evident from the embodiments and examples tofollow.

Maintaining an inert gas environment applies to such applications asfood preservation, including beverages and frozen articles, cigar andtobacco preservation, minimizing oxidation to optics and numismatics,moisture prevention in substantially sealed boxes, shielding sensitiveelectronics, ammunition/gun storage, museum preservation of itemssensitive to the environment (such as vintage documents), andcontrolling chemical reactions. Desiccants have served many applicationsfor controlling moisture while backfilling a closed container with aninert gas has proven to be an effective method to concentrate thecontained environment with the inert gas. Additionally, pulling vacuumon a container has proven an effective method to minimize the oxygen,for example, in a contained environment.

The afore-mentioned backfilling example requires an auxiliary tank andmeans of a connection from the tank to the closed container.Unfortunately, if a leak occurs over time, there is no additional supplyof inert gas introduced into the closed container. Such a situation canprove substantially ineffective, particularly if the container is leftunchecked for a long amount of time. Such an example could be anumismatic collection deposited in a safety deposit box. A carefulperson may include a desiccant with the collection or backfill a closedcontainer with an inert gas. Should the container leak, the entireeffort has been ineffective. Additionally, a fuel cell may require thata hydrogen and/or oxygen chamber remain pressurized and the presentinvention can support this need.

Minimizing oxidation to optics also similarly applies to the abovenumismatic example. Many telescopes are completely exposed to theelements thus requiring a user to consistently clean delicate mirrors.More complex systems are closed but after time, some optics require thatthe coatings be stripped off and recoated primarily due to oxidationand/or cleaning the critical surfaces. An inert environment would helpto reduce moisture and oxidation problems in delicate optics.

A chemist may require a concentration of a certain gas such as an inertenvironment to control or prevent a chemical reaction. A small devicecapable of reliable delivery of such a gas would be very useful in suchan application.

A slow gas delivery directly to a plant's root system has beencommercially available at least in the form of nutrient sticks thatrelease beneficial nutrients upon contact with water, for example. In ahydroponic application, a slow release of a gas to the water solutionhas typically been accomplished via a pressure regulator attached to alarge storage bottle such as to control pH or increase carbon dioxidelevels.

Aquariums have benefited from the introduction of gases into the waterfor reasons such as maintaining pH or changing gas concentration levels.Acidic and basic chemicals are used, sometimes in the form of gases. Along-term delivery device is not available.

On a heavy equipment vehicle that requires consistent lubrication at itsrotating joints, a mechanic typically crawls around the vehicle andlubricates each joint individually on a regular basis. Acontrolled-release delivery of a compressed gas could be harnessed toinject lubricants directly into all joints thus only requiringoccasional inspections and lubricant/compressed gas cartridgereplacement. Similarly, applications in elevators, conveyor systems,bridges and other applications that may be exposed to the elementsand/or less than easily accessible are equally suited for such alubrication system.

Maintaining a positive pressure on a closed system is also an aspect ofthe permeation invention. No pressure regulator is utilized. Rather,slow permeation of the compressed gas fills a container. Excessivepressures are prevented by providing a blow-off or check valve that iseasily available in the current market. Maintenance of a positivepressure on a system minimizes the introduction of foreign particlesinto the positive pressure environment, similar to the function of aclean room.

Many current art compressed gas dispensers, particularly the modelsmanufactured by Genuine Innovations, Inc. in Tucson, Ariz. U.S.A. aremanufactured to dispense a non-threaded neck compressed gas cartridge, athreaded neck compressed gas cartridge, or capable of dispensing bothspecies with the same dispenser. U.S. Pat. No. 6,843,388 titled:Compressed gas cartridge dispensing system allowing interchangeable useof different capacity compressed gas cartridges and novel storagefeature by Holiars, filed Jul. 22, 2002 exemplifies the capabilities ofthe current art compressed gas dispensers.

One feature of current art compressed gas dispensers is a lance housingthat has been used in part to contain the high pressure from acompressed gas cartridge. Historically, lance housings have beenmanufactured from metal such as brass. A lance housing also provides anexcellent recess or pocket for a seal that is used to contain thecompressed gas in a lanced cartridge. A lance housing can featureinternal threads that are used to mate with a compressed gas cartridgealso exhibiting a threaded portion. A lance housing sometimes exhibitsno threads to mate with a compressed gas cartridge and can accept onlynon-threaded varieties.

The compressed gas cartridge dispenser comprising a predictablepermeation rate will function with any of these differing types ofthreaded and non-threaded lance housings and compressed gas cartridges.The preferred embodiment and alternative embodiments will be exemplifiedin the following paragraphs and in the FIGS.

The following embodiments will describe the afore-mentioned prior-artand the present invention. Additionally, with the aid of figures, oneskilled in the art will be able to understand and appreciate theembodiments to follow.

OBJECTS AND ADVANTAGES

Accordingly, several objects and advantages of the present inventionwill be presented in the following paragraphs followed by a thoroughdisclosure of each accompanying embodiment in the DETAILED DESCRIPTION.

In light of the above-mentioned problems, it is therefore an object ofthe present invention to provide a simple method of manufacturing acompressed gas permeation dispenser therefore minimizing material andlabor expenses.

Another object of the present invention is to provide a permeationdispenser capable of disposal after use.

Another object of the permeation dispenser is the ability to predict theleak rate thus dispensing life.

It is another object of the present invention to utilize as little metalas possible in a lance housing and incorporate as many features andcomponents as possible out of injection moldings, particularly foraffordable manufacturing reasons.

Further objects and advantages will become apparent in the followingparagraphs. Solely and in combination, the above objects and advantageswill be illustrated in the exemplary figures and accompanyingembodiments to follow.

BRIEF DESCRIPTION OF THE DRAWINGS

The figures are exemplary of different embodiments of the presentinvention. Each illustration conveys the invention and is not to beconsidered as limiting, rather, exemplary to the scope and spirit of thepresent invention. Like components in the figures share identicalnumbering.

FIG. 1A illustrates an exemplary front view of a compressed gascartridge permeation dispenser, according to an embodiment of thepresent invention;

FIG. 1B illustrates a cross-section view of the exemplary compressed gascartridge permeation dispenser from FIG. 1 comprising a permeation sealsituated about a cartridge piercing lance;

FIG. 2A illustrates another exemplary front view of a compressed gascartridge permeation dispenser, according to an embodiment of thepresent invention;

FIG. 2B illustrates a cross-section view of the compressed gas cartridgepermeation dispenser from FIG. 2A;

FIG. 3A illustrates another exemplary front view of a compressed gascartridge permeation dispenser having a piston sealed by a permeableseal, according to an embodiment of the present invention;

FIG. 3B illustrates a cross-section view the compressed gas cartridgepermeation dispenser from FIG. 3A;

FIG. 4 illustrates experimentally-derived permeation rate data forcarbon dioxide gas permeating through a silicone elastomeric element, inaccordance with an embodiment of the present invention;

FIG. 5 illustrates experimentally-derived permeation rate data forcarbon dioxide gas permeating through a combination of one buna and twourethane elements, in accordance with an embodiment of the presentinvention;

FIG. 6 illustrates experimentally-derived permeation rate data forcarbon dioxide gas permeating through a buna rubber element, inaccordance with an embodiment of the present invention.

DETAILED DESCRIPTION

The following paragraphs will detail, at minimum, the best mode of thepresent invention. The exemplary figures and description of theinvention as it is exemplified in each figure is representative of thecurrent invention and the scope of the invention disclosure is notintended to be limited by the exemplary teachings. Like physicalstructure in different figures share the same identifying numbers.

FIGS. 1A and 1B respectively illustrate front and cross-section views ofan exemplary compressed gas cartridge permeation dispenser comprising apermeation seal situated about a cartridge piercing lance, in accordancewith an embodiment of the present invention. A compressed gas cartridge100 situates within a permeation dispensing body 105. Exemplified inFIG. 1B, compressed gas cartridge 100 is shown punctured by a piercinglance 110, urged into place by a cap 111 and the high pressure fromcompressed gas cartridge 100 is contained by a permeation seal 115 bymeans of compressing permeation seal 115 between a lance seat 120 and acartridge face 125. A high pressure zone 130 is defined by the pressurecontained area created by permeation seal 115. A low pressure seal 135locates in a seat 140, preferably integrated into the inside diameter ofdispensing body 105. Low pressure seal 135 provides a seal betweencompressed gas cartridge 100 and permeation dispensing body 105.

As gas permeates from high pressure zone 130, through permeation seal115, and eventually will exit out of an outlet 140. Outlet 140 canconceivable vent to the atmosphere or outlet 140 can fluidly attach toanother device so, for example, work can be performed on the device bythe slow delivery of gas. Throughout these paragraphs, exemplary usageexamples are discussed that can be applied to such a permeationdispenser.

FIGS. 2A and 2B respectively illustrate front and cross-section views ofanother exemplary compressed gas cartridge permeation dispenser having apermeation element, in accordance with an embodiment of the presentinvention. No compressed gas cartridge is illustrated in FIG. 2A or 2Bbut situates within permeation dispensing body 205 and is lanced throughany lancing means known in the art. A high pressure zone 230 isillustrated that is contained in part by a permeation element 215 andpermeation body 205. Permeation element 215 can be composed of anymaterial that is semi-permeable such as from a family of rubber, denselysintered metal, or any other suitable material that experimentally isdetermined appropriate to provide a desired permeation rate.

FIGS. 3A and 3B respectively illustrate front and cross-section views ofanother exemplary compressed gas cartridge permeation dispenser having apiston sealed by a permeable seal, in accordance with an embodiment ofthe present invention. A permeation body 305 has a piston 315 situatedwithin its bore. Piston 315 rests against a bottom bore 325 ofpermeation body and comprises a seal 310 residing in a seat 311. Seal310 functions as the permeation element in this embodiment and can beeasily changed out to different materials should one desire faster orslower permeation rates. Additionally, seal 310 and piston 315 diameterscan be adjusted to increase or decrease the permeation surface area. Ahigh pressure zone 330 is illustrated that is contained in part bypiston 315 and seal 310 assembly and permeation body 305. A compressedgas cartridge and lancing means are not illustrated in FIG. 3A or 3B butlancing means are so common in the art that the FIGS. concentrate on theimmediate invention. A vent 320 allows permeated gas to escapepermeation body 305 and like in other embodiments, can fluidly attach toanother device, tubing, or nothing.

FIG. 4 graphically illustrates experimentally-derived data for asilicone permeation element situated about a cartridge-piercing lance,such as embodied in FIG. 1, subjected to full cartridge pressure. Theweight of a full compressed gas cartridge commonly called a 12-gram isabout 81.5 grams. The 12-gram is descriptive of cartridge contentsweight and will vary depending on the amount of cartridge fill and bygas properties such as density and if the gas undergoes a phase changewhile compressed, etc.

The compressed gas cartridge was lanced and weighed on day one of theexperiment. The cartridge was weighed every seven days for two monthsand the data logged. Surprisingly, the data illustrates that thepermeable element provides a substantially linear leak-rate that wouldtake this 12-gram cartridge about 63 days to become exhausted.

A gas such as carbon dioxide changes phase to a liquid when compressedinto a compressed gas cartridge. Cartridge pressure remains constant asgas escapes from the cartridge due to the remaining liquid in thereservoir. When no additional liquid remains, cartridge pressuretypically tapers down rapidly. The substantially linear leak rate isprobably attributed to the constant vapor pressure against the permeableelement.

FIG. 5 graphically illustrates experimentally-derived data for acombination of permeation elements comprising different permeablematerials such as buna rubber or urethane, all three located atdifferent locations and individually subjected to cartridge pressure.Similarly to the data of FIG. 4, a 12-gram compressed gas cartridge waslanced while cartridge contents pressure was contained by each of thethree permeation elements, each allowed to vent to the atmosphere inthis embodiment.

The 12-gram compressed gas cartridge in this experiment weighed about 98grams when full. The lanced compressed gas cartridge was weighed onceevery seven days for four months and the data logged. Again, thepermeation rate was substantially linear but this time, cartridgeexhaustion would require approximately 444 days.

FIG. 6 graphically illustrates experimentally-derived data for apermeation element of buna rubber subjected to cartridge pressure.Similarly to the data of FIGS. 4 and 5, a 12-gram compressed gascartridge was lanced while cartridge contents pressure was contained byone permeation element, allowed to vent to the atmosphere in thisembodiment.

The 12-gram compressed gas cartridge in this experiment weighed about111.1 grams when full. The lanced compressed gas cartridge was weighedonce every seven days for four months and the data logged. Again, thepermeation rate was substantially linear but this time, cartridgeexhaustion would require approximately 1110 days, or greater than threeyears.

One skilled in the art could readily experiment using permeable elementshaving larger or smaller areas and of differing materials to tailor apermeation rate. Fortunately for the linear behavior that describespermeation rates, a short data-gathering term provides foresight for oneto predictably estimate the exhaustion date for such a system.

Additionally, one could stack permeation elements in series and/orparallel to tailor permeation to different locations at varying rateswhile utilizing the same compressed gas cartridge.

An embodiment introduced in the BACKGROUND section was a plant rootcarbon dioxide delivery system. A compressed gas cartridge containingliquefied carbon dioxide could be nested into a small capsule comprisinga permeation element and a vent hole or series of vent holes such thatpermeated gas would exit through a vent hole. One would simply lance thecompressed gas cartridge for example by threading on a cap that forcesthe cartridge into a piercing lance. The capsule could then be insertedinto soil around the base of a plant thus deliver a trickle of carbondioxide directly to a root area. Chances are that plant roots would bedrawn towards the carbon dioxide source thus increasing theeffectiveness of a permeation delivery. One could easily attach venttubing to the vent hole(s) and dispense in one or more locations.

Reducing oxidation to numismatics or optics as introduced in theBACKGROUND section could be accomplished with the gas permeationinvention as well. One could lance a compressed gas cartridge in apermeation dispenser having a known dispense time, for example 3 months.Then one could bag or seal the chamber with the permeation dispenserwithin. Experimentation and container sealing capability would determineif a blow-off valve or check valve would be needed. A slightly positivepressure would probably reduce the chances of foreign particles beingintroduced into the container. Dozens of commercially available checkvalve style devices such as duckbill valves, umbrella valves, andflapper valves that will open at a determined pressure are commonlyavailable therefore they will not be discussed here.

Similarly, preservation of fine tobaccos such as cigars could easilyjustify the small cost of an inert gas permeation device that wouldprotect cigar freshness. A small container could be attached to apermeation dispenser whereby the container could be opened and closedwithout the need to replace an unused compressed gas cartridge.

Constant lubrication can be achieved through this gas permeationtechnology. One exemplary method of accomplishing constant lubricationwould be to connect a grease reservoir to a zerk fitting, for example ona mining truck. The grease reservoir would be sealed from the elementsand would fluidly connect to a permeation dispenser having a knownpermeation rate. Permeated gas from the compressed gas cartridge coulddrive a piston above the grease reservoir (ever so slowly) thus provideconstant lubrication to a component.

Chemical reactions could be controlled with the present gas permeationdispenser. A chemist could utilize the benefits of a controlled releasegas to provide an inert environment for some reaction process such as byconcentrating one type of gas into a chamber. Once a permeation rate isknown, a flow meter attached to a regulator and a storage bottle may goby the wayside in some applications in favor for the simplicity of thisdelivery system.

Compressed gas cartridge pressures vary as a function of temperaturechanges, therefore one may need to consider the permeation rates atdifferent pressures. Depending on the degree of consistency desired forpermeation, one could utilize averaging as well as experimental data todetermine an average flow rate. Additionally, statistical weather dataor climate control information could also be integrated into averagingcompressed gas cartridge temperatures and pressures.

1. A compressed gas cartridge permeation dispenser, comprising: ahousing formed to include a chamber therein to house at least onecompressed gas cartridge; a high pressure zone in fluid communicationwith said chamber; wherein: a portion of said housing defining said highpressure zone comprises a permeation element; a compressed gas permeatesfrom said high pressure zone through said permeation element at a linearrate over time; said compressed gas cartridge does not comprise aregulator; said housing does not comprise an outlet other than saidpermeation element.